Compounds containing sterically hindered alkyl amines or sterically hindered oxyalkyl amines, and particularly the moiety
wherein R1 is alkyl, R2 is alkyl, R3 is H or alkyl, R4 is H or alkyl, R5 is H or alkyl, R6 is H or alkyl, R7 is alkyl, and R8 is alkyl are known. When A is alkyl, such compounds are known as hindered amine light stabilizers, or HALS; when A is oxyalkyl, such compounds are known as NORHALS.
The utility of HALS and NORHALS as radical scavengers and polymer stabilizers is well recognized in the art, and is described in, for example, the Journal of Macromolecular Science Part A, 35:7, 1327-36 (1998) and The Journal of Macromolecular Science Part A, 38:2, 137-58 (2001), as well as in JP 2001270859, U.S. Pat. No. 4,983,737 (Grant), and U.S. Pat. No. 5,442,071 (Grant). Such compounds are known to protect polymers from adverse effects of actinic radiation, such as visible and ultraviolet light.